Abstract: Correction steering for a linearly movable irrigation system, consisting of interconnected pipes carried by motorized irrigation towers, whereby at least one irrigation tower constitutes a steering unit for correction of the irrigation system in the case of an angular deflection occurring with respect to the guideway, which deflection is automatically detected by sensors arranged on a bar located in the area of the irrigation tower pertaining to the steering unit, which sensors are in operational contact with the guideway; the bar is a sensor arm (12) which is supported to rotate about a vertical axle (13); the axle (13) is arranged at one of the irrigation towers (1) of the steering unit and the sensor arm (12) is connected with the support (24) located at the outer end of the pipe (5).

Abstract: A turbine, particularly for a sprinkler system, comprises a rotor mounted on a shaft so as to be rotatable about a rotor axis and having a plurality of curved vanes attached to the wheel rim, a variable nozzle and a control device for control of the flow of water through the turbine. The control device is mounted in a ring shaped space, is a part of the nozzle and a part of the wall of the ring shaped space and the control device controls the size of both an annular clearance between the turbine wheel and the control device and the cross section of the nozzle so that the cross section of the nozzle and the annular clearance are correlated with each other. Advantageously the control device may be a broad surface curved plate mounted on a pivot shaft so as to be pivotable partly between two parallel walls of a fixed part of the nozzle formed by the turbine housing and shaped to follow the radius of curvature of the outer periphery of the rotor.